goHDR: Technical Details

The natural world presents our visual system with a wide range of colours and intensities. Furthermore, the scene may be constantly changing with, for example, significant differences in lighting levels going from outside to inside or simply as the sun goes behind some clouds etc. A human eye can see detail in regions that vary by 1:104 at any given eye adaptation level.

A traditional camera, on the other hand, is only capable of capturing a limited range of lighting in any scene, i.e. Low Dynamic Range (LDR). The actual range captured depends on the exposure and f-stop setting of the camera. The remainder of the image outside this limited range is either under- or over-exposed. Images that can reproduce a large portion of the luminance dynamic range available in the real world are known as High Dynamic Range (HDR) images.

HDR imagery offers a more representative description of image-based digital content by storing data with a higher bit-depth per pixel than the more conventional LDR images. HDR images are typically either created in computer graphics or generated from a number of static images.

These are the 4 exposures for building a HDR image

-2 Stops

0 Stops

2 Stops

4 Stops

Merged into a tone mapped HDR picture

False colour image

A HDR video system capable of capturing dynamic HDR images, covering at least 20 f-stops, at full high-definition resolution, at 30 frames-per-second, did not exist … until now!

WMG, International Manufacturing Centre, University of Warwick, Coventry, CV4 7AL, United Kingdom